Steel rule dies for cutting and scoring as well as embossing sheets of cardboard and flexible materials have been fabricated from wood, laminated wood, resinated and impregnated woods, and metal "furniture" in which the steel rule cutting knives and scoring rules have been fitted into slots cut into the die body of the wood or metal and held in position by various means including the introduction of plastic materials such as epoxy resins into slots or cavernous openings in the die base to anchor securely the cutting rules and scoring rules from displacement. The semi-rigid or rigid plastic materials that have been employed as well as other rule retaining means have been time consuming to fabricate and costly to build. The life of steel rule dies that have been encavitated for supporting the steel rules by introducing plastic materials to support the rules to formulate a solid base material have not been commercially successful.
The reusable counterplates for cutting and scoring boxboard or paper board to form carton blanks must be accurately constructed for reuse on hundreds of thousands or millions of impressions and cuttings necessitating precision fabrication and highly durable materials for retaining the cutting and scoring plates or rules in position in their slots within the base or supporting die member.
The female counter plate for receiving the cutting and scoring rules must be accurately fabricated to receive the cutting and scoring rules to avoid misalignment and resulting inferior cutting and scoring of the final product.
One of the primary problems with steel rule scoring dies has been the fabrication of the female counter in which the time consuming process of chemical etching has been utilized which has been extremely costly and time consuming. Computer controlled milling of the counter plate has also been costly and time consuming.
It is an objective of the present invention to provide a steel rule scoring die and counter plate in which the steel rule cutting and scoring rules may be very accurately positioned and retained in the male die, and the female counter plate may be accurately matched with the requisite shallow slots into which the scoring rules are operatively inserted to provide the requisite score lines in the work material to reduce to a minimum torn or severed slots in the workpiece.
A further objective of this invention is to provide a steel rule die set for cutting and scoring material which has a metal face plate from which steel cutting and scoring rules are imbedded and project from the metal face plate and are retained fineries by precisely cut openings for retention without extraneous plastic materials enabling the steel cutting and scoring members to cooperate with a female metal counterplate in which laser cut complementary score line openings are provided to cooperatively receive the score members of the male die with the counter plate having secured thereto a back-up plate covering the score line openings.
Yet another objective of this invention is to provide a female counterplate having a metal face with laser cut complementary score line openings that are precisely aligned with the steel rule scoring members.